noun (plural paramecia)

Contact with protozoa, the tremendously varied group of more sophisticated single-celled microbes that includes amoeba and paramecium, has also been greatly reduced in the developed world by water and food treatment measures.

In 1911, he reported on the effect of hematoporphyrin and light on a paramecium and red blood cells and described skin reactions in mice exposed to light after hematoporphyrin administration.

Parameciums have a permanent feeding mechanism, consisting of a funnel-shaped gullet into which food is drawn by the combined action of the cilia. They feed on small organisms such as bacteria and even other smaller protozoa.